WO2015122058A1

WO2015122058A1 - Gas engine and method for controlling operation thereof

Info

Publication number: WO2015122058A1
Application number: PCT/JP2014/078611
Authority: WO
Inventors: 勇紀小柴; 和雄小倉; 雄太古川
Original assignee: 三菱重工業株式会社
Priority date: 2014-02-17
Filing date: 2014-10-28
Publication date: 2015-08-20
Also published as: JP2015151959A; JP6239402B2

Abstract

The objective of the present invention is to improve operating efficiency and reduce combustion fluctuation in a gas engine that is equipped with a combustion chamber and an auxiliary chamber and that controls the supply of a fuel gas with a check valve. This gas engine, which controls the supply of a fuel gas to an auxiliary chamber (4) by means of a check valve (6) the opening/closing of which is determined by the difference in pressure between the fuel gas supply pressure and the cylinder pressure, is equipped with: a fuel gas amount calculation device (30) that calculates the amount of fuel gas supplied to the auxiliary chamber (4); a fuel gas supply pressure control device (40) and a pressure control valve (41) that control the supply pressure of the fuel gas supplied from an auxiliary gas supply path (14) to the auxiliary chamber (4); and a valve-open timing/valve-open period detection device (50) that detects the valve-open timing and the valve-open period of the check valve (6). The fuel gas supply pressure control device (40) and the pressure control valve (41) adjust the supply pressure of the fuel gas on the basis of detection values for the valve-open timing and the valve-open period.

Description

Gas engine and operation control method thereof

The present invention relates to a gas engine operated using fuel gas such as natural gas as fuel and an operation control method thereof, and in particular, a gas engine provided with a sub chamber in a combustion chamber to control supply of fuel gas with a check valve It relates to the operation control method.

A gas engine is operated using fuel gas such as natural gas as fuel, and generally has a sub-chamber in addition to the main chamber as a combustion chamber. Then, the air-fuel mixture is ignited in the sub chamber to generate a torch flame, and the torch flame is ejected toward the main chamber to burn the air-fuel mixture in the main chamber. Note that the air-fuel mixture that is denser than the main chamber is supplied to the sub-chamber, and the fuel gas is supplied via a supply path separate from the main chamber.

FIG. 4 is a cross-sectional view of an essential part showing a configuration example around the sub chamber in the conventional gas engine having the sub chamber in the combustion chamber.
In the illustrated gas engine, a main chamber 60, which is a main combustion chamber, is defined between a piston (not shown) and the cylinder head 1, and further, an upper portion of the cylinder head 1 4 are formed. The sub chamber 4 is in communication with the main chamber 60 via the injection hole 3.

Further, reference numeral 6s in the figure is a check valve insertion hole, and a check valve 6 for controlling supply of fuel gas is provided. The interior of the check valve insertion hole 6s is defined in two spaces of the check valve upper chamber 28 and the check valve lower chamber 29 by the installation of the check valve 6. An auxiliary chamber gas supply passage 14 is connected to one check valve upper chamber 28 to communicate with a fuel gas supply source (not shown), and a communication hole 5 is formed between the check valve lower chamber 29 and the auxiliary chamber 4. It is connected by. The check valve 6 described above allows only the flow from the fuel gas supply source to the sub chamber 4.
In the figure, reference numeral 1a is a water chamber, 6a is a center line of the check

valve insertion hole

6s, 9 is a check valve holder, and 10 is a spark plug.

In such a gas engine, for example, as disclosed in the following patent documents, a plurality of sub-chamber fuel supply passages are formed in parallel (see Patent Document 1), and the opening time of the solenoid valve is extended. There is known a technique for controlling the flow rate of fuel gas to the sub chamber by the configuration in which the throttle portion is provided in the sub chamber gas flow path (see Patent Document 2).

JP, 2009-221937, A JP, 2013-113256, A

By the way, in a gas engine in which the sub chamber 4 is installed, as a fuel gas supply device to the sub chamber 4, a check valve 6 whose opening period is determined by a pressure difference is adopted. Since the valve opening period of the check valve 6 is determined by the pressure difference between the supply pressure of the fuel gas supplied to the sub chamber 4 and the in-cylinder pressure on the main chamber 60 side, the flow rate of the fuel gas supplied to the sub chamber Amount) difficult to control. In addition, such a gas engine is not clear at which time within one cycle the check valve 6 is open and whether there is cyclic variation in the valve opening period.
As described above, the gas engine that supplies the fuel gas to the auxiliary chamber 4 using the check valve 6 changes the valve opening timing and the valve opening period of the check valve 6 depending on the operating conditions. It has the problem of being difficult to do properly.

In addition, the behavior of the check valve 6 may change due to age-related changes such as mixing of foreign matter (oil, fine particles, etc.), wear, change in spring constant, and the like. Such a change in behavior of the check valve 6 is also one of the factors that make it difficult to control the flow rate of the fuel gas.
Furthermore, the methane value and components of the fuel gas may change depending on the environment such as the region and the season, and the pressure in the sub-chamber at the same output may change due to aging of the gas engine. It becomes a factor which makes the flow control of gas difficult.

From such a background, in a gas engine having a sub chamber in the combustion chamber and controlling the supply of fuel gas with a check valve, the flow rate control of the fuel gas is improved to improve the operating efficiency and suppress the combustion fluctuation. It is desirable to realize.
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a gas engine having a sub-chamber in a combustion chamber and controlling supply of fuel gas with a check valve. It is an object of the present invention to provide a gas engine and its operation control method which can realize improvement and suppression of combustion fluctuation.

The present invention adopts the following means in order to solve the above-mentioned problems.
A gas engine according to a first aspect of the present invention comprises a main chamber defined between a piston and a cylinder head, a sub chamber communicated with the main chamber via a nozzle hole, and a fuel gas in the sub chamber. A gas engine for controlling the fuel gas supply to the sub-chamber by a non-return valve whose opening and closing period is determined by the pressure difference between the fuel gas supply pressure and the in-cylinder pressure on the main chamber side A fuel gas amount calculation unit for calculating an amount of fuel gas supplied to the sub chamber; a fuel gas supply pressure control portion for controlling a fuel gas supply pressure supplied from the sub chamber gas supply passage to the sub chamber; And an open valve state detection unit for detecting an open valve timing and an open valve period of the check valve, and the fuel gas supply pressure control unit is configured to detect the open valve timing and the open valve period. Adjusting the fuel gas supply pressure; It is intended.

According to the gas engine of the first aspect, the fuel gas amount calculation unit that calculates the amount of fuel gas supplied to the sub chamber, and the fuel that controls the fuel gas supply pressure supplied from the sub chamber gas supply path to the sub chamber A gas supply pressure control unit, and an open valve state detection unit for detecting an open valve timing and an open valve period of a check valve, and the fuel gas supply pressure control unit detects the open valve timing and the detected value of the open valve period. Since the fuel gas supply pressure is adjusted on the basis of this, it becomes possible to control the flow rate of the fuel gas appropriately, reflecting the valve opening timing and the valve opening period at which the check valve has actually operated.

In the above gas engine, the fuel gas supply pressure is adjusted by raising the fuel gas supply pressure when the valve opening timing is later than the setting and the valve opening period is shorter than the setting, and the valve opening timing is set. It is preferable to lower the fuel gas supply pressure more quickly and when the open period is longer than the setting, whereby the supply amount (flow rate) of the fuel gas can be properly adjusted. That is, by raising and increasing the fuel gas supply pressure, the flow rate of the fuel gas increases, so it is possible to increase the fuel gas supply amount when the valve opening period is shorter than the setting, and conversely, the fuel gas supply pressure By lowering and lowering the flow rate of the fuel gas decreases, it is possible to reduce the amount of fuel gas supplied when the opening period is longer than the setting.

In this case, it is preferable that the fuel gas supply pressure be adjusted according to the change in the in-cylinder pressure, whereby the composition of the fuel gas at the time of startup (at start-up) of the gas engine and at low speed operation Even under operating conditions where the in-cylinder pressure on the main chamber side changes, such as when changing and when the operating environment changes, it is possible to properly adjust the amount (flow rate) of fuel gas supplied.

Further, in the above gas engine, the valve opening state detection unit is provided in one representative cylinder selected from a plurality of fuel gas supply pressure control units of other cylinders so as to perform control following the representative cylinder. As a result, the number of valve open state detectors can be minimized, and the amount of fuel gas supplied can be properly adjusted.

In a gas engine operation control method according to a second aspect of the present invention, a main chamber defined between a piston and a cylinder head, a sub chamber communicated with the main chamber via an injection hole, and the sub chamber And a sub-chamber gas supply passage for supplying the fuel gas to the sub-chamber by a check valve whose opening and closing period is determined by the pressure difference between the fuel gas supply pressure and the in-cylinder pressure on the main chamber side. A control method of a gas engine to be controlled, wherein a fuel gas amount to be supplied to the sub chamber is calculated by a fuel gas amount calculating unit, and from the sub chamber gas supply passage to the sub chamber so as to become the fuel gas amount. The fuel gas supply pressure to be supplied is controlled by the fuel gas supply pressure control unit, and the fuel gas supply pressure is adjusted based on the detection value obtained by detecting the valve opening timing and the valve opening period of the check valve. It is said that.

According to the operation control method of the gas engine of the second aspect, the amount of fuel gas supplied to the sub chamber is calculated by the fuel gas amount calculation unit, and the amount of fuel gas is calculated from the sub chamber gas supply passage. The fuel gas supply pressure supplied to the chamber is controlled by the fuel gas supply pressure control unit, and the fuel gas supply pressure is adjusted based on the detection value obtained by detecting the valve opening timing and the valve opening period of the check valve. This enables appropriate fuel gas flow control reflecting the valve opening timing and the valve opening period at which the stop valve has actually operated.

In a gas engine operation control method according to a third aspect of the present invention, a main chamber defined between a piston and a cylinder head, a sub chamber communicated with the main chamber through an injection hole, and the sub chamber And a sub-chamber gas supply passage for supplying the fuel gas to the sub-chamber by a check valve whose opening and closing period is determined by the pressure difference between the fuel gas supply pressure and the in-cylinder pressure on the main chamber side. A control method of a gas engine to be controlled, wherein a fuel gas amount to be supplied to the sub chamber is calculated by a fuel gas amount calculating unit, and from the sub chamber gas supply passage to the sub chamber so as to become the fuel gas amount. The fuel gas supply pressure to be supplied is controlled by the fuel gas supply pressure control unit, and the valve opening timing and opening period of the check valve detected in advance by the valve opening state detection unit, the fuel gas supply pressure and the cylinder internal pressure Create a database that shows the relationship with It is characterized in that the adjustment of the fuel gas supply pressure based on the database.

According to the operation control method of the gas engine of the third aspect, the amount of fuel gas supplied to the sub chamber is calculated by the fuel gas amount calculation unit, and the amount of fuel gas is calculated from the sub chamber gas supply passage. The fuel gas supply pressure supplied to the chamber is controlled by the fuel gas supply pressure control unit, and the valve opening timing and opening period of the check valve detected in advance by the valve opening state detection unit, the fuel gas supply pressure and in-cylinder pressure As the database indicating the relationship between the two is created and the fuel gas supply pressure is adjusted based on the database, the check valve actually operated even if the gas engine does not have the valve opening state detection unit Appropriate fuel gas flow control reflecting the valve opening timing and the valve opening period is enabled. That is, since the valve opening state detection unit is used only at the time of creation of the database, it becomes possible to easily apply it to an existing engine in which the valve opening state detection unit is difficult to install constantly.

According to the present invention described above, the gas engine having the auxiliary chamber in the combustion chamber and controlling the supply of fuel gas with the check valve has improved operating efficiency in a wide operating range by improving the flow control of the fuel gas. It is possible to improve the combustion and to suppress the combustion fluctuation.

FIG. 1 is a cross-sectional view of an essential part showing a configuration example around a sub chamber of a gas engine having a sub chamber in a combustion chamber as one embodiment of a gas engine and an operation control method thereof according to the present invention. It is an explanatory view showing adjustment of fuel gas supply pressure according to change of an valve-opening period, a crank angle is made into a horizontal axis, lift amount (check valve lift amount) and pressure of a check valve are shown on the vertical axis ing. It is an explanatory view showing adjustment of fuel gas supply pressure according to change of cylinder internal pressure, a crank angle is made into a horizontal axis and lift amount (check valve lift amount) and pressure of a check valve are shown on a vertical axis There is. It is principal part sectional drawing which shows the structural example around a subchamber as a prior art example of the gas engine provided with the subchamber in the combustion chamber.

Hereinafter, an embodiment of a gas engine and an operation control method therefor according to the present invention will be described based on the drawings.
FIG. 1 is a cross-sectional view of an essential part showing the periphery of a sub chamber of a gas engine according to the present embodiment. This gas engine includes a main chamber 60 which is a main combustion chamber, a sub chamber 4, and a sub chamber gas supply passage 14, and in the sub chamber 4, the mixture is ignited by the spark plug 10 to generate a torch flame. By discharging the torch flame toward the main chamber 60, the mixture in the main chamber 60 is burned.

In the illustrated embodiment, a main chamber 60 which is a main combustion chamber is defined between the piston (not shown) and the cylinder head 1. In the upper portion of the cylinder head 1, a sub chamber cap 2 is fixed by being surrounded by the water chamber 1a, and a sub chamber 4 is formed inside the sub chamber cap 2. The sub chamber 4 is communicated with the main chamber 60 through the injection hole 3 and receives the supply of the fuel gas through a sub chamber gas supply passage 14 connected to a fuel gas supply source (not shown).
The upper surface of the sub-chamber base 2 is pressed to the cylinder head 1 by pressing the upper surface of the sub-chamber with the spark plug retainer 13 and the clamp member 12, and the spark plug 10 is mounted in the spark plug retainer 13 via the mounting sheet surface. It is fixed.

A check valve insertion hole 6 s is formed in the spark plug retainer 13 at a position above the sub chamber 4. At the lower part of the check valve insertion hole 6s, a check valve 6 supported by the check valve holder 9 to control the supply of fuel gas is installed. By installing the check valve 6, two spaces of the check valve upper chamber 28 and the check valve lower chamber 29 are defined in the check valve insertion hole 6s, and the check valve is formed. The lower chamber 29 and the sub chamber 4 are in communication with each other by the communication hole 5.
Further, one end of a sub chamber gas supply passage 14 is connected to the side portion of the spark plug retainer 13 so as to communicate with the check valve upper chamber 28.

The check valve 6 of the present embodiment allows the flow in the direction from the check valve upper chamber 28 toward the check valve lower chamber 29, and the pressure between the fuel gas supply pressure and the in-cylinder pressure on the main chamber 60 side. The difference (differential pressure) determines the open / close period. That is, the check valve 6 is a valve that opens and closes based on the pressure difference between the fuel gas supply pressure and the in-cylinder pressure on the main chamber 60 side, and controls the fuel gas supply to the sub chamber 4.
Then, the gas engine of the present embodiment supplies the fuel gas amount calculation device 30 serving as a fuel gas amount calculation unit that calculates the amount of fuel gas supplied to the sub chamber 4, and supplies the sub chamber 4 from the sub chamber gas supply passage 14. A fuel gas supply pressure control device 40 and a pressure control valve 41 serving as a fuel gas supply pressure control unit for controlling the fuel gas supply pressure, and an open valve state detection unit for detecting the valve opening timing and valve opening period of the check valve 6 A valve opening timing and valve opening period detecting device (hereinafter referred to as a "detecting device") 50 is provided.

For example, an engine speed 31, a load signal 32, a fuel property 33, and an outside air temperature 34 are input to the fuel gas amount calculation device 30 as necessary. The engine rotation speed 31, the load signal 32, the fuel property 33 and the outside air temperature 34 shown here are detection data such as an operating condition and the like input to the normal gas engine.
The fuel gas amount calculation device 30 calculates the amount of fuel gas supplied to the sub chamber 4 based on the input detection data and the like. The amount of fuel gas calculated here is input to the fuel gas supply pressure control device 40.

The detection device 50 is a device that detects (measures) a situation where the check valve 6 actually opens and closes using, for example, the gap sensor 51, and inputs it to the fuel gas supply pressure control device 40 or the fuel gas amount calculation device 30. is there. That is, since the valve body of the check valve 6 is moved by the opening and closing operation, the detecting device 50 continuously measures the distance L with the valve body by the gap sensor 51 such as an over current type mutation sensor, and changes in the measured value. To detect the valve opening timing and the valve opening period of the check valve 6. The detected value is input to the fuel gas supply pressure control device 40.

In this case, the valve body of the check valve 6 receiving the spring bias opens the fuel gas to the auxiliary chamber 4 when the in-cylinder pressure is low and the pressure difference with the fuel gas supply pressure is large such as in the suction stroke. The fuel gas supply is stopped by closing the valve when the supply pressure is high and the pressure difference with the fuel gas supply pressure is small, such as in the exhaust stroke. That is, for a substantially constant fuel gas supply pressure, the in-cylinder pressure fluctuates in accordance with the stroke of the gas engine, so the check valve 6 compares the pressure in the main chamber 60 (in-cylinder pressure) with the fuel gas supply pressure. When the pressure difference is larger than the predetermined value, the lift amount is increased and the valve moves upward to open. Conversely, when the pressure difference between the pressure in the main chamber 60 and the fuel gas supply pressure is smaller than the predetermined value, the lift is increased. Move downward to close the valve.

The fuel gas supply pressure control unit comprising the fuel gas supply pressure control device 40 and the pressure control valve 41 adjusts the fuel gas supply pressure based on the valve opening timing of the check valve 6 and the detected values of the valve opening period. It is something to do. That is, the fuel gas supply pressure control device 40 calculates the fuel gas supply pressure based on the fuel gas amount, the valve opening timing and the valve opening period input from the fuel gas amount calculating device 30 and the detecting device 50, and this fuel gas An opening control signal of the pressure control valve 41 is outputted so as to be the supply pressure.
The pressure control valve 41 operates to change the opening degree in accordance with the opening degree signal. Therefore, the fuel gas supplied pressure to the sub chamber 4 is adjusted according to the opening degree of the pressure control valve 41 for the fuel gas supplied to the sub chamber gas supply passage 14 at a substantially constant pressure.

Thus, the gas engine that adjusts the fuel gas supply pressure can reflect the valve opening timing and the valve opening period when the check valve 6 actually operated in the fuel gas flow control, and the appropriate fuel gas flow rate Control is possible. In other words, feedback control is performed by reflecting the valve opening timing and the valve opening period at which the check valve 6 actually operated with respect to the opening control of the pressure control valve 41 that adjusts the fuel gas supply pressure that has a correlation with the flow rate. Therefore, it becomes possible to supply the appropriate fuel gas supply amount to the sub chamber 4 reflecting the actual situation of the check valve 6.

Hereinafter, adjustment of the fuel gas supply pressure of the fuel gas supply pressure control device 40 will be specifically described.
The fuel gas supply pressure control device 40 raises the fuel gas supply pressure when the valve opening timing of the check valve 6 is later than the setting and the valve opening period is shorter than the setting based on the input data from the detecting device 50. The fuel gas supply pressure is reduced when the valve opening timing is earlier than the setting and the valve opening period is longer than the setting.

When the valve opening timing of the check valve 6 is later than the setting and the valve opening period is shorter than the setting, it can be determined that the supply amount of fuel gas is smaller than the predetermined supply amount. On the other hand, an opening control signal in the direction to increase the fuel gas supply pressure from the set value, that is, an opening control signal in the direction to increase the opening is output. As a result, since the fuel gas supply amount also increases with the increase of the fuel gas supply pressure, it is possible to adjust and correct the shortage of the fuel gas supply amount caused by the valve opening timing and the valve opening period of the check valve 6 it can.

Further, when the valve opening timing of the check valve 6 is earlier than the setting and the valve opening period is longer than the setting, it can be determined that the supply amount of the fuel gas is larger than the predetermined supply amount. The valve 41 outputs an opening degree control signal in a direction to lower the fuel gas supply pressure from the set value, that is, an opening degree control signal in a direction to narrow the opening degree. As a result, since the fuel gas supply amount also decreases with the decrease of the fuel gas supply pressure, it is possible to adjust and correct the increase of the fuel gas supply amount caused by the valve opening timing and the valve opening period of the check valve 6 it can.

That is, for example, as shown in FIG. 2, in the range from the case where the valve opening period Ta is at the valve opening timing a1 / the valve closing timing b1, to the valve opening period Tb at the valve opening timing a2 / the valve closing timing b2. The valve opening timing or opening period of the check valve 6 is adjusted by adjusting the fuel gas supply pressure supplied to the sub chamber 4 within the pressure range .DELTA.P of P1 to P2 based on the input data from the detection device 50. It is possible to adjust and correct the increase and decrease of the fuel gas supply amount generated by In FIG. 2, the fuel gas supply pressure is P1 when the valve opening period Ta is at the valve opening timing a1 / valve closing timing b1, and the valve opening period Tb is at the valve opening timing a2 / valve closing timing b2. The fuel gas supply pressure is P2.

By controlling the fuel gas supply pressure as described above, even in the gas engine that performs fuel gas supply using the check valve 6, the appropriate fuel gas supply timing and supply gas flow rate to the auxiliary chamber 4 are adjusted. It becomes possible. Then, by appropriately adjusting the fuel gas supply to the sub chamber 4, it is possible to improve the thermal efficiency of the gas engine and to suppress the combustion fluctuation under the rated conditions.
In addition, the control of the fuel gas supply pressure described above maps the target valve opening timing or valve opening period of the check valve 6 by the engine speed 31 and the load signal (kW signal) 32, and is actually obtained by the detection device 50 In comparison with the valve opening timing or the valve opening period, it is also possible to control by 3D mapping by adding the fuel property 33 or the outside air temperature 34.

By the way, in the gas engine described above, the in-cylinder pressure on the main chamber 60 side changes, such as when the gas engine is started (at start-up), at low revolutions, when the composition of the fuel gas changes, when the operating environment changes, etc. Even in such an operating condition, the detection device 50 can grasp the valve opening timing and the valve opening period of the check valve 6. Therefore, the fuel gas supply pressure can also be adjusted according to the in-cylinder pressure change of the main chamber 60.

Specifically, as shown in FIG. 3, when the in-cylinder pressure changes as Ps1 to Ps3, the fuel gas supply pressure is adjusted as P1 to P3 so that the valve opening period T becomes a predetermined value. Do. In other words, the differential pressure between the fuel gas supply pressure and the in-cylinder pressure is adjusted to a predetermined value such that the valve opening timing a / the valve closing timing b and the valve opening period T become set values.
In this case, the lowest in-cylinder pressure is P1 which is the lowest with respect to Ps1, and the highest in-cylinder pressure is P3 which is the lowest with respect to Ps3. The differential pressure with the internal pressure can be made constant.

For example, at the time of startup of the gas engine, the pressure of the fuel gas supplied to the auxiliary chamber 4 may be gradually raised according to the valve opening timing and the valve opening period detected by the detecting device 50 to smoothly start up. It becomes possible. That is, the fuel gas supply pressure is adjusted to an optimum pressure according to the in-cylinder pressure at the time of start-up that gradually rises, and an operation in which the amount of fuel gas supplied is optimized can be performed.
Therefore, at the time of startup of the gas engine, it is possible to shorten the startup time and reduce the amount of fuel gas consumption, and to perform stable engine startup. Further, the gas engine performing such control can improve the thermal efficiency of the gas engine and suppress the combustion fluctuation at the time of operation at a low rotation speed or a low load.

In the above-described gas engine, even when the composition of the fuel gas changes and the amount of heat changes, depending on the valve opening timing and the valve opening timing of the check valve 6 that supplies the fuel gas to the auxiliary chamber 4, The supply pressure of the fuel gas supplied to the sub chamber 4 can be adjusted.
That is, by controlling the pressure of the fuel gas supplied to the auxiliary chamber 6 based on the measurement result of the check valve 6 obtained from the detection device 50, it is possible to cope with the composition change of the fuel gas and the regional difference. . Therefore, without changing the specifications of the gas engine each time, it becomes possible to cope with fuel gas with different heat quantity and temperature condition fluctuation at the time of operation, etc., and one type of gas engine can cover many areas and operation conditions. It becomes possible to offer.

By the way, when the gas engine includes a plurality of cylinders, the above-described detection device 50 may be provided for all cylinders, but may be provided for only one representative cylinder (representative cylinder) selected from a plurality of cylinders. . In this case, for the other cylinders, the fuel gas supply pressure control device 40 and the pressure control valve 41 constituting the fuel gas supply pressure control unit may perform control in accordance with the representative cylinder.
Thus, by providing the detection device 50 in the representative cylinder, the number of the detection devices 50 can be minimized, and the amount of fuel gas supplied can be properly adjusted.

In the gas engine having the configuration of the embodiment described above, the amount of fuel gas supplied to the sub chamber 4 is calculated by the fuel gas amount calculation unit 30, and the amount of fuel gas is obtained from the sub chamber gas supply passage 14 to the sub chamber 4. The fuel gas supply pressure supplied to the fuel gas is controlled by the fuel gas supply pressure control device 40 and the pressure control valve 41, and the detection device 50 detects the valve opening timing and the valve opening period of the check valve 6 based on detected values. An operating method for adjusting the gas supply pressure is possible.
Therefore, appropriate fuel gas flow control can be performed by feedback control reflecting the valve opening timing and valve opening period when the check valve 6 actually operated.

Moreover, although the gas engine was equipped with the detection apparatus 50 in the driving method of the gas engine mentioned above, in other embodiment, the valve opening timing and valve opening of the non-return valve 6 detected beforehand by the detection apparatus 50 A database indicating the relationship between the period, the fuel gas supply pressure and the in-cylinder pressure may be created, and the fuel gas supply pressure may be adjusted based on this database. That is, in this operation method, the fuel gas supply pressure is controlled based on a database created in advance, instead of providing a dedicated detection device 50 for the gas engine.

If such a gas engine operation method is adopted, even if the gas engine is not equipped with the detection device 50, the appropriate fuel gas that reflects the valve opening timing and the valve opening period at which the check valve 6 actually operated. Flow control becomes possible. That is, since this operation method uses the detection device 50 only at the time of creation of a database, it becomes possible to easily apply it to an existing engine where the permanent installation of the detection device 50 is difficult.

As described above, the gas engine according to the present embodiment described above, that is, the gas engine having the auxiliary chamber 4 in the combustion chamber and controlling the supply of the fuel gas by the check valve 6 is a non-return valve detected by the detection device 50 Since the fuel gas supply pressure supplied to the auxiliary chamber 4 is feedback-controlled based on the operation of the valve 6, the flow rate control of the fuel gas is improved, and the operation efficiency can be improved and the combustion fluctuation can be suppressed in a wide operation area. . In addition, the thermal efficiency of the gas engine can be improved and combustion fluctuation can be suppressed, and efficient combustion can be achieved in a wide operating range, and also combustion fluctuation can be suppressed.
The present invention is not limited to the above-described embodiment, and can be appropriately modified without departing from the scope of the invention.

Reference Signs List 1 cylinder head 2 auxiliary chamber cap 3 injection hole 4 auxiliary chamber 5 communication hole 6 check valve 6s check valve insertion hole 9 check valve holder 10 spark plug 14 auxiliary chamber gas supply path 30 fuel gas amount calculation device (fuel gas amount Operation unit)
40 Fuel gas supply pressure control device (fuel gas supply pressure control unit)
41 Pressure control valve (fuel gas supply pressure control unit)
50 Opening timing / opening period detection device (opening detection unit)
51 gap sensor 60 main room

Claims

A main chamber defined between the piston and the cylinder head, a sub chamber in communication with the main chamber via the injection hole, and a sub chamber gas supply passage for supplying a fuel gas to the sub chamber;
A gas engine controlling a fuel gas supply to the sub-chamber by a check valve whose open / close period is determined by a pressure difference between a fuel gas supply pressure and a cylinder internal pressure on the main chamber side.
A fuel gas amount calculation unit that calculates a fuel gas amount to be supplied to the sub chamber;
A fuel gas supply pressure control unit that controls a fuel gas supply pressure supplied from the sub chamber gas supply path to the sub chamber;
And an open valve state detection unit that detects an open valve timing and an open valve period of the check valve.
The said fuel gas supply pressure control part is a gas engine which adjusts the said fuel gas supply pressure based on the detected value of the said valve opening timing and the said valve opening period.
Adjustment of the fuel gas supply pressure is
If the valve opening timing is later than the setting and the valve opening period is shorter than the setting, the fuel gas supply pressure is increased;
The gas engine according to claim 1, wherein the fuel gas supply pressure is lowered when the valve opening timing is earlier than a setting and the valve opening period is longer than the setting.
The gas engine according to claim 1, wherein the adjustment of the fuel gas supply pressure is performed according to a change of the in-cylinder pressure.
The fuel gas supply pressure control unit of the other cylinder is provided with the valve opening state detection unit in one representative cylinder selected from a plurality of cylinders, and the fuel gas supply pressure control unit performs control in accordance with the representative cylinder. The gas engine described in.
A main chamber defined between the piston and the cylinder head, a sub chamber in communication with the main chamber via the injection hole, and a sub chamber gas supply passage for supplying a fuel gas to the sub chamber;
An operation control method of a gas engine, comprising: controlling a fuel gas supply to the auxiliary chamber by a check valve whose open / close period is determined by a pressure difference between a fuel gas supply pressure and a cylinder internal pressure on the main chamber side.
The fuel gas amount supplied to the sub chamber is calculated by the fuel gas amount calculation unit, and the fuel gas supply pressure supplied from the sub chamber gas supply passage to the sub chamber is controlled so as to become the fuel gas amount. While controlling in the department,
An operation control method of a gas engine, which adjusts the fuel gas supply pressure based on a detected value at which an open valve timing and an open period of the check valve are detected.
A main chamber defined between the piston and the cylinder head, a sub chamber in communication with the main chamber via the injection hole, and a sub chamber gas supply passage for supplying a fuel gas to the sub chamber;
An operation control method of a gas engine, comprising: controlling a fuel gas supply to the auxiliary chamber by a check valve whose open / close period is determined by a pressure difference between a fuel gas supply pressure and a cylinder internal pressure on the main chamber side.
The fuel gas amount supplied to the sub chamber is calculated by the fuel gas amount calculation unit, and the fuel gas supply pressure supplied from the sub chamber gas supply passage to the sub chamber is controlled so as to become the fuel gas amount. While controlling in the department,
A database indicating the relationship between the valve opening timing and the valve opening period of the check valve detected in advance by the valve opening state detection unit, the fuel gas supply pressure and the in-cylinder pressure is created, and the fuel gas is generated based on the database The operation control method of the gas engine which adjusts supply pressure.